摘要
中子照相技术是无损检测技术之一,它具有其他无损检测技术无可替代的特点和优点,能够获得很多其它传统技术不能得到的重要信息。在无损检测技术中,由于中子照相具有特殊的功能,其应用范围日益扩大。在欧美和亚洲一些工业发达国家,中子照相已走上了商业化的轨道,它与X射线和γ射线照相相互补充,在工业、国防、航天、考古和生物医学等方面得到了广泛的应用,发挥了重要的作用。
中子照相图像是指在中子辐照场里,中子穿透被测物质后通过中子成像系统所获取到的图像。它携带着被测物质的内部结构等信息。由于在中子成像的过程中,不可避免地会受到γ射线污染、中子散射、CCD电子噪声等因素的影响,使得所获取到的中子照相图像会发生降质,如噪声严重、细节模糊等,不利于分析、判别被测物质的内部信息。
本论文研究工作致力于研究适合于中子照相图像的去噪声、去模糊等图像处理技术,以便能够获取关于物质内部的更多的信息,丰富中子成像无损检测技术的研究内容。为此,论文在理解中子成像原理的基础上,详细分析了引起中子照相图像降质的主要因素。
为提取中子照相图像的有用信息,便于进行图像分析研究,引入图像分割技术。图像分割是由图像处理过渡到图像分析的关键步骤,在图像工程中占据重要的位置。一方面,它是目标表达的基础,对特征测量有重要的影响。另一方面,因为图像分割及其基于分割的目标表达、特征提取和参数测量等将原始图像转化为更抽象更紧凑的形式,使得更高层的图像分析和理解成为可能。
在图像分割的基础上,围绕中子照相图像所含有的各种噪声和性质,我们借鉴X光图像处理的某些经验,采用滤波,反色,二值化,数学形态学等多种图像处理算法,并在原有算法的基础上提出降噪形态学算子,降噪效果显著。本文还针对大理石下花的中子照相图像障碍物边缘去除问题,提出了扩展的Roberts算子,并对其加以改进与Hough变换结合,得到令人满意的花的图像。
Neutron photography is one of the detecting technology without destroyed. There are some characters and advantages that others don’t have, and it can get some important messages that other traditional technology can’t get. The application of the neutron photography is enlarging in the detecting technology without destroyed because its peculiar function. In many industry countries of occident and Asia, the neutron photography is on its commercial track. It’s complementary with radiography andγ-ray imaging makes it is applied extensively in the field of industry, national defence , spaceflight, archaeology and biomedicine and have an important effect in the fields.
The image of neutron photography is formed by the imaging system when neutrons in the radiancy field traverse the detected matter. They carry information of the inner structure. In the process of the creation of image, the image is occasionally different from primitive scenery, because of the influence of various factors. It is not propitious to analyse and distinguish the information of the inner structure because of the severity yawp and illegible detail.
This paper is mainly about image processing about the smear and blurred neutron photography image, in order to get more inner information of pictures. The paper therefore analyses the main factors that depress the image qualities based on apprehending the neutron photography theory.
In the interest of getting useful information and making it easy to analyse of the neutron photography image, we adhibit image segmentation technology. It is the linchpin from image processing to image analysis and take an important degree in the image engineering. On one hand, it is the base of goal expression and has an important effect on character measure. On the other hand, image segmentation technology transform the original image into abstract form which make it possible to analyse and understand the picture intensively.
Neutron photography image have many kinds of smear and property, so we use some experience of X-ray image processing for reference and adopt filter, color reverse, mathematics morphologic processing measure to reduce smear of the image. The effect is obvious.
This paper is in allusion to wipe off the fringe in neutron photography image of the flower below marble and put forward patulous Roberts operator. Then improve on it and combine with Hough transform and get satisfying image of flower.
引文
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